Research Interests                               

I have broad interests in plant community and landscape ecology. My research focuses primarily on boreal forest dynamics, disturbance regimes, succession, and interactions between large herbivores (e.g. beavers, caribou) and plant communities.  Current studies include (1) community and ecosystem response to ground fires in mixed hardwood-hemlock forests, (2) investigating the role of forest management practices on forest fire behavior and intensity, and (3) use of stable isotope analysis to elucidate food web pathways between litter, bacteria, periphyton, and macrophytes in stream systems.

Recent Projects (Collaborators in Parentheses):

1. Aquatic Macrophyte Succession in Beaver Ponds (Andy Ray, Heather Ray)

Trends in macrophyte community properties were examined across a 40-year chronosequence of beaver ponds in northern Minnesota.  We focused on life history traits of aquatic plants (e.g. dispersal mechanisms) and landscape properties (size of pond, isolation from other ponds and lakes) to explain trends during succession (Ray et al. 2001).  A subsequent paper (Ray et al. 2004) linked successional mechanisms for fish and macrophyte communities.

2.  Landscape impact of beaver excavation and impoundments in fens (Lou Torretti, Josh Vandemark)

GIS analysis was used to document the extent of canal networks and impounded peatland in Seney NWR, MI and Badoura Swamp, MN. We used field measurements to calculate the volume of displaced peat and how beaver excavation impacts the fen-upland interface.  We are currently doing research on how canals increase landscape connectivity 

3. Seed bank dynamics following the 1999 Tower Lake Fire (Sarah Pratt)

We initially documented herbaceous and woody response to this crown fire near Republic, MI, identifying sensitive species and life history strategies of species that responded favorably to the fire (e.g. seed bank, post-fire seed dispersal).  We developed a landscape model to predict the seedbank response of bristly sarsaparilla, bush honeysuckle, and pale corydalis.

4. Comparison of Old Growth Structural Features in Different Forest Types (Joanne Wolford)

We are comparing various structural feature (tree size and age distributions, canopy stratification, and coarse woody debris) across 4 old-growth forest types: red pine, white cedar, hemlock-white pine, and maple-basswood in the Upper Peninsula.

5. Subalpine Forest Succession: Clark's Nutcracker Brings Life and Death to a Forest (Joe Donnegan)

We used tree-ring analysis to reconstruct 300-years of post-fire succession in subalpine forests dominated by limber pine, Engelmann spruce, and subalpine fir. We quantified rates of succession, tree mortality and recruitment trends along a moisture gradient. The avian frugivore Clark's Nutcracker caches limber pine seeds in post-fire sites in a classic mutualism, but we demonstrated that the establishment patterns by these birds directly influence the longevity of limber pine and rates of succession centuries later (Donnegan & Rebertus 1999).

6. Blowdown History and Landscape Patterns in the Fuegian Andes (Veblen, Kitzberger, Roovers)

We mapped and dated 94 blowdowns along a belt-transect across the Andes in monospecific Nothofagus pumilio to determine the return intervals and spatial distribution of major windthrow events.  We also addressed the interaction of wind disturbance and guanaco browsing in stand development and the stability of alpine timberline in the region (Rebertus et. al. 1997).

7.  Savanna Dynamics (Dr. Sean Jenkins, Dr. Bruce Burns)

Over 1800 trees have been mapped and aged in two 1-ha plots in "virgin" savanna in central Missouri, where we are focusing on the relationship between fire history and spatial demography of oaks (Jenkins & Rebertus 1995, and in prep.).  Over a more extensive area we have been examining the role of canopy gaps in savanna formation (Rebertus & Burns 1997).

8. Ecological impact of a ground fire in northern hemlock-hardwood forests (Dr. Albert Meier) 

We are measuring the loss of organic matter in different forest community types, comparing  the selectivity of tree mortality in surface vs. ground fires, and studying the interaction between ground fire damage and secondary windfall.   

 

 

 

 

 

9. 500-year fire history in red pine stands along Lake Superior (Becky Torretti) 

We are using tree-ring dating of scars to reconstruct the fire histories of pineries at the mouths of the Yellow Dog and Huron rivers along Lake Superior. These detailed chronologies will better reveal the history and burning "strategies" of Native Americans in the area and their impact of the development of red pine forests.

Selected Publications

Ray, H.L., A.M. Ray, and A.J. Rebertus.  2004. Rapid establishment of fish in isolated peatland beaver ponds. Wetlands 24: 399-405.       

Ray, A.M, A.J. Rebertus, and H.L. Ray 2001. Succession of aquatic macrophytes in Minnesota beaver ponds. Canadian J. Botany 79: 487-499

Donnegan, J.A. and A.J. Rebertus. 1999. Rates and mechanisms of subalpine forest succession along an environmental gradient. Ecology 80: 1370-1384.

Batek, M.J., Rebertus, A.J., Schroeder, W.A., Haithcoat, T.L., Compas, E. and R.P. Guyette. 1999. Reconstruction of early nineteenth century vegetation and fire regimes in the Missouri Ozarks. J. Biogeography 26: 397-412.

Rebertus, A.J., Kitzberger, T., Veblen, T.T., and Roovers, L.M. 1997. Blowdown history and landscape patterns in Nothofagus forests in southern Andes, Tierra del Fuego. Ecology 78:678-692

Rebertus, A.J. and B.R. Burns. 1997. The importance of gap processes in the development and maintenance of oak savannas and dry forests. Journal of Ecology 85: 635-645

Veblen, T.T., C. Donoso, T. Kitzberger, and A.J. Rebertus. 1996. Ecology of southern Chilean and southern Argentinean Nothofagus forests. Pp. 293-353 In: Veblen, T.T., Hill, R.S., and Read, J. (eds.). Ecology and biogeography of Nothofagus forests. Yale University Press, New Haven, Ct.

Roovers, L.M. and Rebertus, A.J. 1993. Stand dynamics and conservation of old-growth spruce-fir forests in the Colorado Front Range. Natural Areas Journal 13:256-267.

Rebertus, A.J. and Veblen, T.T. 1993. Partial wave formation in old-growth Nothofagus forests of Tierra del Fuego. Bulletin of the Torrey Botanical Club 120:461-470.

Veblen, T.T., Hadley, K.S., Reid, M.S., and Rebertus, A.J. 1991. Stand response to spruce beetle outbreak in Colorado subalpine forests. Ecology 72:213-231.

Rebertus, A.J., Williamson, G.B., and Moser, E.B. 1989. Fire induced changes in Quercus laevis spatial pattern in Florida sandhills. Journal of Ecology 77:638-650.

Rebertus, A.J., Williamson, G.B., and Moser, E.B. 1989. Longleaf pine pyrogenicity and turkey oak mortality in Florida xeric sandhills. Ecology 70:60-70.

Rebertus, A.J. 1988. Crown shyness in a tropical cloud forest. Biotropica 20:338-339.

Rebertus, A.J. 1986. Use of bog habitats by beavers in north-central Minnesota. American Midland Naturalist 116:240-245
 
 

Graduate Student Theses

Mulder, J.   in prep.   Stable carbon isotope analysis of DIC derived carbon in periphyton of a low order boreal forest stream.

Torretti, B.  2003.  Traditional stories for non-traditional sources: tree-rings reveal historical use of fire by Native Americans on Lake Superior's southern shore.

Pratt, S.D.  2003.  Early vegetation dynamics following the 1999 Tower Lake Fire in northern Michigan.

Torreti, L.  2002. Beaver engineering and zoogeomorphological alterations to large fen landscapes in northern Michigan and Minnesota.

Wolford, J.E.  2002 Characteristics of old-growth forests in the Upper Peninsula of Michigan.

Ray. A.M.  1999.  Aquatic macrophyte succession in beaver ponds.

Dietrich, C.  1998.  Understory vegetation patterns in oak savannas of the Missouri Ozarks.

Jenkins, S.E. 1997. Spatial demography of an Ozark Savanna (Ph.D. Dissertation)

Donnegan, J.A. 1996.  Rates of subalpine forest succession along an environmental gradient.

 

Answer:  Hudson Bay Lowlands ("Martian Plains")